1. Field of the Invention
The present invention concerns the testing of transducers such as piezoelectric transducers. In order to test such transducers it is necessary to simulate the normal acoustic impedance presented to them in the medium in which they are intended to operate. One application involving the use of transducers is in generating or detecting acoustic signals under water.
2. Description of the Related Art
In British Patent Specification No. 2217952B there is described a loading probe or rod for use in testing transducers and which comprises an elongated body capable of simulating the normal acoustic impedance presented to a transducer to be tested by the medium in which the transducer is to operate, the rod having a bore in its main body portion containing a core of material having a close match of acoustic impedance with the material of the rod but a higher acoustic loss factor. In this prior specification a preferred embodiment of the rod is manufactured from an acrylic polymer and has a tapered bore in its main body portion.
However, this arrangement has proved difficult and expensive to manufacture and the present invention is concerned with meeting this problem.
British Patent Specification No. 2192514 discloses a measurement probe for carrying out the same type of measurement operation and in which a piezo electric transducer is mounted in the main body of the probe after the impedance matching network. The present invention is also concerned with providing a measurement probe or loading rod which can give more accurate results than that disclosed in the aforesaid prior specification.